Comparison of radiographic results after minimally invasive, hybrid, and open surgery for adult spinal deformity: a multicenter study of 184 patients.

OBJECT: Various surgical approaches, including open, minimally invasive, and hybrid techniques, have gained momentum in the management of adult spinal deformity. However, few data exist on the radiographic outcomes of different surgical techniques. The objective of this study was to compare the radiographic and clinical outcomes of the surgical techniques used in the treatment of adult spinal deformity. METHODS: The authors conducted a retrospective review of two adult spinal deformity patient databases, a prospective open surgery database and a retrospective minimally invasive surgery (MIS) and hybrid surgery database. The time frame of enrollment in this study was from 2007 to 2012. Spinal deformity patients were stratified into 3 surgery groups: MIS, hybrid surgery, and open surgery. The following pre- and postoperative radiographic parameters were assessed: lumbar major Cobb angle, lumbar lordosis, pelvic incidence minus lumbar lordosis (PI-LL), sagittal vertical axis, and pelvic tilt. Scores on the Oswestry Disability Index (ODI) and a visual analog scale (VAS) for both back and leg pain were also obtained from each patient. RESULTS: Of the 234 patients with adult spinal deformity, 184 patients had pre- and postoperative radiographs and were thus included in the study (MIS, n = 42; hybrid, n = 33; open, n = 109). Patients were a mean of 61.7 years old and had a mean body mass index of 26.9 kg/m(2). Regarding radiographic outcomes, the MIS group maintained a significantly smaller mean lumbar Cobb angle (13.1°) after surgery compared with the open group (20.4°, p = 0.002), while the hybrid group had a significantly larger lumbar curve correction (26.6°) compared with the MIS group (18.8°, p = 0.045). The mean change in the PI-LL was larger for the hybrid group (20.6°) compared with the open (10.2°, p = 0.023) and MIS groups (5.5°, p = 0.003). The mean sagittal vertical axis correction was greater for the open group (25 mm) compared with the MIS group (≤ 1 mm, p = 0.008). Patients in the open group had a significantly larger postoperative thoracic kyphosis (41.45°) compared with the MIS patients (33.5°, p = 0.005). There were no significant differences between groups in terms of pre- and postoperative mean ODI and VAS scores at the 1-year follow-up. However, patients in the MIS group had much lower estimated blood loss and transfusion rates compared with patients in the hybrid or open groups (p < 0.001). Operating room time was significantly longer with the hybrid group compared with the MIS and open groups (p < 0.001). Major complications occurred in 14% of patients in the MIS group, 14% in the hybrid group, and 45% in the open group (p = 0.032). CONCLUSIONS: This study provides valuable baseline characteristics of radiographic parameters among 3 different surgical techniques used in the treatment of adult spinal deformity. Each technique has advantages, but much like any surgical technique, the positive and negative elements must be considered when tailoring a treatment to a patient. Minimally invasive surgical techniques can result in clinical outcomes at 1 year comparable to those obtained from hybrid and open surgical techniques.

Clinical Improvement Through Surgery for Adult Spinal Deformity: What Can Be Expected and Who Is Likely to Benefit Most?

STUDY DESIGN: Multicenter, prospective, nonconsecutive, surgical case series from the International Spine Study Group. OBJECTIVES: To evaluate the extent of clinical improvement after surgery for adult spinal deformity (ASD) based on minimal clinically important difference (MCID) and baseline measures. SUMMARY OF BACKGROUND DATA: For ASD, evaluation of surgical treatment success using clinical scores should take into account baseline disability and pain and the improvement defined relative to the MCID. METHODS: Inclusion criteria included operative patients (age >18 years) with baseline and 2-year SRS-22 scores. Normative values for the SRS scores were included and improvement for patients was expressed in number of MCIDs. At baseline, patients were classified by differences in activity and pain scores from normative values in four groups: "worst," "severe," "poor," and, "moderate." At 2 years after surgery, patients were classified into four groups based on their change in SRS score as follows: "no improvement or deterioration," "mediocre," "satisfactory," or "optimal." Distinction among curve types was also performed based on the SRS-Schwab ASD classification. RESULTS: A total of 223 patients (age = 55 ± 15 years) were included. At baseline, for 77% of the patients, the worst scores were in Activity or Pain. At baseline, the distribution was 36% "worst," 28% "severe," 19% "poor," and 17% "moderate." Patients with sagittal malalignment only were more likely to be in the "worst" state (54%). The overall distribution of improvement was as follows: 24% no improvement or deterioration, 17% mediocre, 25% satisfactory, and 33% optimal. Forty-one percent of baseline "moderate" patients achieved no improvement. Of the baseline "worst" patients, 20% achieved no improvement, and 36% and 19% achieved "satisfactory" and "optimal" improvement, respectively. CONCLUSION: Overall, 24% of patients did not experience improvement after surgery. Patients with baseline severe disability were more likely to perceive improvement than patients with less disability. LEVEL OF EVIDENCE: Level II.

How the neck affects the back: changes in regional cervical sagittal alignment correlate to HRQOL improvement in adult thoracolumbar deformity patients at 2-year follow-up.

OBJECT Regional cervical sagittal alignment (C2-7 sagittal vertical axis [SVA]) has been shown to correlate with health-related quality of life (HRQOL). The study objective was to examine the relationship between cervical and thoracolumbar alignment parameters with HRQOL among patients with operative and nonoperative adult thoracolumbar deformity. METHODS This is a multicenter prospective data collection of consecutive patients with adult thoracolumbar spinal deformity. Clinical measures of disability included the Oswestry Disability Index (ODI), Scoliosis Research Society-22 Patient Questionnaire (SRS-22), and 36-Item Short-Form Health Survey (SF-36). Cervical radiographic parameters were correlated with global sagittal parameters within the nonoperative and operative cohorts. A partial correlation analysis was performed controlling for C-7 SVA. The operative group was subanalyzed by the magnitude of global deformity (C-7 SVA ≥ 5 cm vs < 5 cm). RESULTS A total of 318 patients were included (186 operative and 132 nonoperative). The mean age was 55.4 ± 14.9 years. Operative patients had significantly worse baseline HRQOL and significantly larger C-7 SVA, pelvic tilt (PT), mismatch between pelvic incidence and lumbar lordosis (PI-LL), and C2-7 SVA. The operative patients with baseline C-7 SVA ≥ 5 cm had significantly larger C2-7 lordosis (CL), C2-7 SVA, C-7 SVA, PI-LL, and PT than patients with a normal C-7 SVA. For all patients, baseline C2-7 SVA and CL significantly correlated with baseline ODI, Physical Component Summary (PCS), SRS Activity domain, and SRS Appearance domain. Baseline C2-7 SVA also correlated with SRS Pain and SRS Total. For the operative patients with baseline C-7 SVA ≥ 5 cm, the 2-year C2-7 SVA significantly correlated with 2-year Mental Component Summary, SRS Mental, SRS Satisfaction, and decreases in ODI. Decreases in C2-7 SVA at 2 years significantly correlated with lower ODI at 2 years. Using partial correlations while controlling for C-7 SVA, the C2-7 SVA correlated significantly with baseline ODI (r = 0.211, p = 0.002), PCS (r = -0.178, p = 0.009), and SRS Activity (r = -0.145, p = 0.034) for the entire cohort. In the subset of operative patients with larger thoracolumbar deformities, the change in C2-7 SVA correlated with change in ODI (r = -0.311, p = 0.03). CONCLUSIONS Changes in cervical lordosis correlate to HRQOL improvements in thoracolumbar deformity patients at 2-year follow-up. Regional cervical sagittal parameters such as CL and C2-7 SVA are correlated with clinical measures of regional disability and health status in patients with adult thoracolumbar scoliosis. This effect may be direct or a reciprocal effect of the underlying global deformities on regional cervical alignment. However, the partial correlation analysis, controlling for the magnitude of the thoracolumbar deformity, suggests that there is a direct effect of cervical alignment on health measures. Improvements in regional cervical alignment postoperatively correlated positively with improved HRQOL.

Radiographic Outcomes of Adult Spinal Deformity Correction: A Critical Analysis of Variability and Failures Across Deformity Patterns.

STUDY DESIGN: Multicenter, prospective, consecutive, surgical case series from the International Spine Study Group. OBJECTIVES: To evaluate the effectiveness of surgical treatment in restoring spinopelvic (SP) alignment. SUMMARY OF BACKGROUND DATA: Pain and disability in the setting of adult spinal deformity have been correlated with global coronal alignment (GCA), sagittal vertical axis (SVA), pelvic incidence/lumbar lordosis mismatch (PI-LL), and pelvic tilt (PT). One of the main goals of surgery for adult spinal deformity is to correct these parameters to restore harmonious SP alignment. METHODS: Inclusion criteria were operative patients (age greater than 18 years) with baseline (BL) and 1-year full-length X-rays. Thoracic and thoracolumbar Cobb angle and previous mentioned parameters were calculated. Each parameter at BL and 1 year was categorized as either pathological or normal. Pathologic limits were: Cobb greater than 30°, GCA greater than 40 mm, SVA greater than 40 mm, PI-LL greater than 10°, and PT greater than 20°. According to thresholds, corrected or worsened alignment groups of patients were identified and overall radiographic effectiveness of procedure was evaluated by combining the results from the coronal and sagittal planes. RESULTS: A total of 161 patients (age, 55 ± 15 years) were included. At BL, 80% of patients had a Cobb angle greater than 30°, 25% had a GCA greater than 40 mm, and 42% to 58% had a pathological sagittal parameter of PI-LL, SVA, and/or PT. Sagittal deformity was corrected in about 50% of cases for patients with pathological SVA or PI-LL, whereas PT was most commonly worsened (24%) and least often corrected (24%). Only 23% of patients experienced complete radiographic correction of the deformity. CONCLUSIONS: The frequency of inadequate SP correction was high. Pelvic tilt was the parameter least likely to be well corrected. The high rate of SP alignment failure emphasizes the need for better preoperative planning and intraoperative imaging.

Effect of spinal deformity on adolescent quality of life: comparison of operative scheuermann kyphosis, adolescent idiopathic scoliosis, and normal controls.

STUDY DESIGN: A prospective multicenter study and retrospective chart review. OBJECTIVE: To compare health-related quality of life (HRQOL) measures and sagittal deformity in operative Scheuermann kyphosis (SK), operative adolescent idiopathic scoliosis (AIS), and normal populations. SUMMARY OF BACKGROUND DATA: No study to date has evaluated patient reported HRQOL measures before surgery in operative patients with SK. METHODS: HRQOL data were prospectively collected pretreatment for operative patients with SK using the SRS-22 outcomes instrument and visual analogue scale (VAS). Comparison was made with the SRS-22 from operative AIS and normal populations. Eighty-six patients with SK enrolled in the prospective study were compared with 184 patients with AIS from a prospective database and 31 normal controls. To study the correlation between T5-T12 kyphosis magnitude and SRS-22 score, patients with AIS and SK were pooled together to create a larger continuum of kyphosis. Analysis of covariance, Pearson correlation analysis, and Bonferroni pairwise comparisons were used to determine statistical differences between group demographics, HRQOL indicators, and radiographical variables. RESULTS: Patients with SK had significantly lower scores in all domains of the SRS-22 than patients with AIS. Patients with SK with a thoracolumbar apex reported significantly lower mean scores in the pain domain than those with a thoracic apex. Significant negative correlations were found between all domains of the SRS-22 and T5-T12 kyphosis-the self-image domain demonstrated the highest correlation (r = 0.37). VAS score in the SK population correlated negatively to the pain, self-image, and mental health domains. CONCLUSION: Increasing sagittal plane deformity as a result of SK has a significant impact on HRQOL as determined by the SRS-22 outcome instrument. In this study, patients with SK reported significantly decreased (worse) scores in all subdomains of the SRS-22 compared with patients with AIS. LEVEL OF EVIDENCE: 1.

Effect of spine fellow training on operative outcomes, affirming graduated responsibility.

STUDY DESIGN: Retrospective review of prospectively collected surgical data. OBJECTIVE: This study sought to determine the effect of fellow education during the course of the academic year (August-July) on surgical outcomes in adolescent idiopathic scoliosis. One surgeon and one type of surgery were chosen to minimize confounding factors. SUMMARY OF BACKGROUND DATA: Educating and training the next generation of physicians and surgeons is necessary for the survival and continuation of medical care. There has been recent momentum to document scientifically that medical education is safe. Spine surgery is complex and demanding, with a steep learning curve, making it an ideal model to detect any potential negative impact of medical education. SUBJECTS: adolescent patients undergoing posterior spinal surgery, between August 2007 and July 2010, by a single senior surgeon at one institution with a fellow as the only surgical assistant. Demographic and perioperative data were collected and then segmented by surgical date into quarters according to the rotations of the academic year. One fellow was included in each quarter during the 4 years, resulting in 16 fellows across the 4 quarters. An analysis of variance model was used to assess differences in operative time, blood loss, length of stay, and complications between the quarters of the year. RESULTS: There were no significant differences between the groups regarding age, sex, or Lenke curve type. No statistically significant differences were found between the 4 quarters of the fellowship year for estimated blood loss, use of cell saver, length of stay, operative time, and complication rate. CONCLUSION: This study is the first to show that fellow education during the course of the academic year did not impact the patient outcomes studied. It is clear that while there is significant academic benefit for the fellows as they complete their spine fellowship, there is no negative impact for patients. LEVEL OF EVIDENCE: 4.